This invention relates to a loose-fill insulation that consists of regularly shaped and uniformly sized pieces of bonded glass fibers that can be pneumatically applied over horizontal building surfaces.
The use of fiber glass blowing wool or loose-fill insulation is well known and is preferred by many contractors because it can be easily and quickly applied to new and old buildings and is a relatively low cost material.
Conventionally, blowing wool is produced from bonded glass fibers which is crushed or pulverized into small sized pieces by a hammer mill. One knonw process for producing blowing wool is disclosed in U.S. Pat. No. 3,584,796, wherein bonded glass fiber material having a density in the range of about 0.2 to 20 per cubic foot, is fed into a hopper in which is located a rotary cutter which severs the material into small pieces. The several material is removed from the cutting area by suction through a sizing screen. Blowing wool produced by these methods is characterized by constituent pieces or nodules that have no uniformity in size, nor regularity in configuration, which results in the tendency of the non-regular nodules to bridge together within some regions of an installed blanket creating excessive voids, and to clump together in other regions. This non-uniform distribution gives forth to non-uniform thermal performance or R values across the insulating blanket.